when did exotics become a thing?

i havent played adopt me in quite a while just joined in every now and then but never really played it/cared about it like i used to. after the fossil egg i quit and recently(maybe september) i got back into it and theres SO many new rules/values/etc and im just curious when that happened? because i specifically remember exotics or preppy pets never being a thing in my time of playing

also how do i know what pets are gonna be exotics? ex. from the new valentines update? are any gonna be exotics/how long will it take until you know?